After a user action in the app sets an alarm, a snackbar says how long
until it rings: "Alarm set for 7 hours and 12 minutes from now". The row
already said "in 7h 12m", but nothing drew the eye to it, so an AM/PM or
wrong-day slip went unnoticed until the morning.
It is raised by switching an alarm on in the list, and in the editor by
picking a time (or keeping a new alarm's default one), arming or
disarming the skip, and changing the repeat days. Day taps wait a second
to settle, so Mon-Fri is one snackbar rather than five; a newer
countdown always replaces the one on screen. Switching the announced
alarm back off takes it back. A switched-off, ringing or snoozed alarm
says nothing, and the AlarmClock intents never reach it, since those
already get the status-bar icon.
AlarmSetCountdown decides what it says, purely, with the row's rounding;
the engine gains upcomingFor(), a read-only resolve of one alarm.
Fixes#19
makiolaj
58c9bfebb1